Yes, I would call ahead first
15 may be a bit too large of a party. But I'm sure if you call the restaurant, they can confirm that.
I'm pretty sure the will try to accommodate a party of 15.
You will need to call and see if they will take a reservation for a party that size. I have seen big groups there in the past.
While eating there I noticed larger parties than the 4 at my table but I don't know you'd have to call and see if they can accommodate you?
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